Vulnerability Details : CVE-2021-46927
In the Linux kernel, the following vulnerability has been resolved:
nitro_enclaves: Use get_user_pages_unlocked() call to handle mmap assert
After commit 5b78ed24e8ec ("mm/pagemap: add mmap_assert_locked()
annotations to find_vma*()"), the call to get_user_pages() will trigger
the mmap assert.
static inline void mmap_assert_locked(struct mm_struct *mm)
{
lockdep_assert_held(&mm->mmap_lock);
VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
}
[ 62.521410] kernel BUG at include/linux/mmap_lock.h:156!
...........................................................
[ 62.538938] RIP: 0010:find_vma+0x32/0x80
...........................................................
[ 62.605889] Call Trace:
[ 62.608502] <TASK>
[ 62.610956] ? lock_timer_base+0x61/0x80
[ 62.614106] find_extend_vma+0x19/0x80
[ 62.617195] __get_user_pages+0x9b/0x6a0
[ 62.620356] __gup_longterm_locked+0x42d/0x450
[ 62.623721] ? finish_wait+0x41/0x80
[ 62.626748] ? __kmalloc+0x178/0x2f0
[ 62.629768] ne_set_user_memory_region_ioctl.isra.0+0x225/0x6a0 [nitro_enclaves]
[ 62.635776] ne_enclave_ioctl+0x1cf/0x6d7 [nitro_enclaves]
[ 62.639541] __x64_sys_ioctl+0x82/0xb0
[ 62.642620] do_syscall_64+0x3b/0x90
[ 62.645642] entry_SYSCALL_64_after_hwframe+0x44/0xae
Use get_user_pages_unlocked() when setting the enclave memory regions.
That's a similar pattern as mmap_read_lock() used together with
get_user_pages().
Products affected by CVE-2021-46927
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-46927
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 7 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-46927
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
1.8
|
3.6
|
NIST | 2024-04-10 |
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
N/A
|
N/A
|
RedHat-CVE-2021-46927 | 2024-02-27 |
CWE ids for CVE-2021-46927
-
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-46927
-
https://git.kernel.org/stable/c/90d2beed5e753805c5eab656b8d48257638fe543
nitro_enclaves: Use get_user_pages_unlocked() call to handle mmap assert - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/3a0152b219523227c2a62a0a122cf99608287176
nitro_enclaves: Use get_user_pages_unlocked() call to handle mmap assert - kernel/git/stable/linux.git - Linux kernel stable treePatch
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